Final answer:
MutS functions in the mismatch repair system by recognizing and binding to mismatched base pairs in DNA, which is essential for correcting errors following DNA replication and preventing mutations.
Step-by-step explanation:
The mismatch repair system is a crucial cellular mechanism that corrects errors introduced during DNA replication, ensuring the genetic material's integrity. Specifically, MutS plays a vital role in this system by recognizing and binding to mismatched base pairs. This process involves MutS identifying mismatches in the DNA—a necessary step before other enzymes can repair the error. Mismatch repair is crucial for preventing mutations that could lead to diseases, including cancer.
Upon recognition of a mismatch, other components of the repair system, such as MutL and MutH in E. coli, are recruited to complete the repair process. MutH cleaves the newly synthesized DNA strand, which is not yet methylated, allowing an exonuclease to excise the portion of the strand containing the incorrect nucleotide. DNA polymerase III then fills in the gap with the correct nucleotide, and DNA ligase seals the strand, restoring the DNA's proper sequence.